GREENVILLE, Miss. - A predominantly African-American church here was badly burned on Tuesday evening, with the words "Vote Trump" spray-painted on the side of the building, an episode that comes amid rising concerns over possible violence in the final days of a polarizing and racially charged presidential race.
Mayor Errick D. Simmons of Greenville said that firefighters, responding to a call around 9:15 p.m., discovered the Hopewell Missionary Baptist Church "engulfed in flames." Fire Chief Ruben Brown said the blaze took about an hour to fully extinguish. The church sanctuary was heavily damaged by heat, fire and smoke, he said.
By Wednesday evening, Mr. Brown said investigators had concluded that the fire was "definitely arson" after discovering "some type of solvent or flammable substance" inside. And Police Chief Delando Wilson said a "person of interest" was being interviewed by authorities "to see if this person was an active participant in this crime, or to rule them out from being a participant."
The 200-member church has been a fixture for more than 110 years in Greenville, a Mississippi Delta city of about 32,000. "Our hearts are broken but are not angry," Carolyn Hudson, the church pastor, said at a news conference called Wednesday by city officials. "But hearts are broken, and we are saddened by what has happened."
No one was injured in the attack.
At the news conference, Chief Wilson said the episode was being investigated as a hate crime.
"We feel that the quote that was placed on the church was basically, it's an intimidation of someone's right to vote whatever way they choose to vote," he said. "So that would be definitely considered a hate crime."
But "as far it being a racial issue," he added, "I can't say that."
The F.B.I. office in Jackson, the state capital, released a brief statement saying that it was "working with our local, state and federal law enforcement partners to determine if any civil rights crimes were committed." The state fire marshal and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives were also assisting with the investigation.
Mississippi's secretary of state, Delbert Hosemann, said Wednesday that he had been in contact with "authorities in Greenville" and the

state Highway Patrol about the attack. Those discussions led him to believe that the burning and vandalism were not committed by "somebody of a political nature," he said.
"The initial work here indicates this is not of a political nature even though there may be something that says 'Vote Trump' on the side of the church," said Mr. Hosemann, a Republican. "So everybody needs to calm down here until we get to the bottom of this."
Like much of the Mississippi Delta, Greenville has struggled economically and has worked to overcome the legacy of slavery. In the mid-20th century, as African-Americans struggled to integrate the Deep South, church bombings were among the ugliest acts of retaliation by recalcitrant white racists.
Greenville today is about 20 percent white and 78 percent black, and the public schools are virtually all black. But Mr. Simmons noted that blacks and whites now pray together every fifth Sunday as part of an event he created.
The mayor said he visited church members Wednesday. "I talked to folks who were fearful," he said. "I talked to people who were intimidated. I talked to people who, quite frankly, were saddened and crying last night. This should not happen in 2016. It happened in the '50s. It happened in the '60s. But we're in 2016."
In a separate phone interview on Wednesday, the mayor said race relations in the city had not really changed with the rise of Mr. Trump. But he blamed the Republican candidate for coarsening the national mood, and said extremists were using his remarks "as an excuse to show their true colors."
Also on Wednesday, about three dozen people gathered in a park along the Greenville waterfront to pray and speak about healing and the primacy of faith over politics. Joining a Methodist preacher, an Episcopal priest and a synagogue president in the cool of the night was Alice Washington, a member of Hopewell.
"We had good church on Sunday," she said, saying it had been some time since she remembered such a good service. "We've been trying to figure out who would do something like this to our church," she said. "Whoever done it, may God bless them."